1. Field of the Invention
The present disclosure generally relates to micro-electronic circuits and in particular but not exclusively, a phase-locked loop that can be integrated into an integrated circuit and equipped with an acoustic resonator.
2. Description of the Related Art
Phase-Locked Loops (PLL) are current electronic circuits that are used in many applications.
They are particularly used in telecommunication systems and specially in mobile telephony where integration of transmitter and receiver electronic circuits within a single semiconductor product, is sought.
The following document “DESIGN TECHNIQUES FOR AUTOMATICALLY TUNED INTEGRATED GIGAHERTZ-RANGE ACTIVE LC FILTERS,” Dandan Li, Yannis Tsividis, IEEE Journal of Solid State Circuits, vol. 37, No. 8, August 2002 describes a control technique using a phase-locked loop.
U.S. Patent 2004/0033794 entitled “RESONATOR CONFIGURATION,” published on Feb. 19, 2004 discloses a process for tuning a resonator mounted on an integrated circuit by means of a second reference resonator also mounted on the same substrate. The reference resonator is used in a VCO-type (Voltage Control Oscillator) circuit to generate a local oscillation frequency. This patent does not indicate how to practically proceed to obtain a precise and effective tuning of the circuit using the resonator.